臭氧对罗氏沼虾育苗池水净化作用的研究

选择臭氧仪合适工作条件：流速为3 L/min,O3与水的混合时间为6～8min。首先以臭氧仪全循环处理罗氏沼虾育苗池水,布苗后每天以臭氧仪原池循环处理池水3～4h。育苗周期内,试验池下换水、不添加任何药物,测得其NO2^--N、NH3-N和COD等各指标的变化范围较对照池相应指标分别下降了18.2%～91.8%、25.0%～39.3%和16.5%～50.0%。试验池幼体较对照池的强壮、变态率高、变态速率快。出苗率为对照组的1.7倍,出池仔虾平均体长与体重分别为对照池1.2与1.4倍。     

罗氏沼虾育苗循环水处理技术与模式

将育苗用水经消毒及沉淀处理后作为试验基础用水,应用泡沫分离器、经预处理的生物滤器和紫外线消毒器等处理罗氏沼虾育苗循环水,使水质得到了有效控制。试验期间,对照池以大量换水及用药等传统方式维持水质,而试验池未曾用药和换水,较对照池节约水67.5%;试验池主要水质指标变化范围如下:NH3 Nm:0～0.010mg·L-1,NO2- N:0.01～0.63mg·L-1,pH:7.48～8.37,CODMn:5.42～12.25mg·L-1,细菌总数:(4.2～130)×103cell·mL-1,弧菌数:(0.2～20)×102cell·mL-1;试验组出苗率为40%,高出对照组33.3%。生产性育苗试验中,试验池与对照池均获得了30%的出苗率。据试验结果及罗氏沼虾育苗特点,提出了处理罗氏沼虾育苗循环水的技术与模式。     

河口区室内幼虾养殖循环水处理技术与模式

利用臭氧与生物滤器循环水处理系统进行室内南美白对虾幼虾养殖。试验期间,按48～72h间隔以臭氧处理养虾循环水2h、曝气2～4h。水处理期间,暂停处理池、养虾池间水循环,过滤系统持续运转。53d中,水处理系统有效控制养殖水质化学指标与微生物指标均在合适范围内,各指标平均值为:NH3-Nt0.41mg·L-1,NO-2-N0.057mg·L-1,COD10.12mg·L-1,氧化还原电位379mV,浑浊度0.6NTU,细菌总数10200cell·mL-1,弧菌数6cell·mL-1;同时获得较高的幼虾成活率(78.3%～80.2%)。根据试验结果与河口水特点,提出了河口区室内养虾循环水处理模式。     

河蟹工厂化育苗中人工半咸水的净化与循环利用

采用室内，室外大循环的水交换形式及生物净化和物理，化学处理相结合的方法，对河蟹育苗废水进行净化与循环利用，可将育苗用人工半咸水的利用率提高２－３倍，节约配水原料５０％。另外把育苗废水的生物净化与单胞藻，轮虫的培养结合在一起，既可净化水质，又能为蟹苗提供大量的生物饵料，试验池蟹苗的成活率较对照池提高１．０－２．５％。     

虾蟹养殖水体环境修复研究

为修复海水虾、蟹养殖环境,进行养虾池水体修复对照试验,试验池采用微生物菌剂、池塘改造、水生动物移植、水质调控以及综合治理等措施进行综合修复,结果显示,与对照池相比,试验池水pH值稳定,氨氮、亚硝酸盐有效降解,实现了尾水净化循环利用。     

室内集约化养虾池以低频率运转水处理系统调控水质效果及氮磷收支

采用低频率运转循环水处理系统(含粗滤器、臭氧仪、气液混合器,蛋白分离器、暗沉淀池等)联用池内设施(微泡曝气增氧机与净水网)开展凡纳滨对虾室内集约化养殖实验。研究了养虾池以水处理系统调控水质效果及氮磷收支。结果表明,养虾水经系统处理后,NO₂-N(53.4%～64.5%)、COD_Mn(53.4%～94.4%)与TAN(31.6%～40.4%)被显著去除,有效改进虾池水质;养殖周期内未换水与用药,虾池主要水化指标均控制在对虾生长安全范围,7号实验池(100 d)与8号对照池(80 d)主要水化指标变化范围:DO分别为 5.07～6.70 mg/L和4.38～6.94 mg/L,TAN 0.248～0.561 mg/L和0.301～0.794 mg/L,NO₂-N 0.019～0.311 mg/L和0.012～0.210 mg/L,COD_Mn 10.88～21.22 mg/L和11.65～23.34 mg/L。7号池对虾生长指数优于8号池(80 d虾病暴发终止),单位水体产量分别为1.398 kg/m²与0.803 kg/m²。氮磷收支估算结果:7号与8号池饲料氮磷分别占总收入:氮93.70%与92.37%,磷98.77%与99.09%;初始水层与虾苗含氮共占总收入6.30%与7.63%,磷共占1.23%与0.91%。总水层(含排污水)氮磷分别占总输出:氮56.45%与59.86%,磷53.26%与55.79%;收获虾体氮磷分别占总输出:氮37.07%与31.94%,磷21.37%与13.11%。7号池饲料转化率较高;池水渗漏与吸附等共损失氮磷分别占总输出:氮7.00%与9.34%,磷25.37%与31.10%。实验结果表明,虾池以低频率运转循环水处理系统联用池内设施可有效控制水质与虾病,具较高饲料转化率。     

粉状微颗粒饵料培育对虾幼体的初步研究

我们在1984年进行了对虾幼体粉状微颗粒饵料的研制和小水体育苗试验，发现在对虾糠虾期和仔虾期投喂粉状微颗粒饵料都能顺利变态，并且每立方米水体出仔虾3～4万尾。1985年将这种粉状微颗粒饵料直接用于生产性育苗试验，对虾从糠虾Ⅰ期至仔虾出池，使用该饵料培育，能顺利发育变态，每立方米水体出仔虾7．5万～9．3万尾。现将试验结果报道如下。     

河蟹工厂化育苗中人工半咸水的净化与循环利用研究

采用室内、室外大循环的水交换形式，将生物净化和物理、化学处理相结合对河蟹育废水进行净化与循环利用，可提高育苗用水利用率2—3倍。节约配水原料50％以上，同时把生物净化与单胞藻，轮虫的培养结合在一起，既达到了净化育苗废水的目的，又为蟹苗提供了大量的生物饵料．蟹苗成活率较对照池提高2．5％．     

室内凡纳滨对虾工厂化养殖循环水调控技术与模式

利用臭氧仪、泡沫分离器和粗滤器等组成的循环水处理系统开展室内凡纳滨对虾工厂化养殖.养殖初始用水及在每次循环处理前的来自虾池的循环水,均置于消毒池以臭氧处理4 h、曝气2 h,初始水经处理细菌总数约杀灭99%,弧菌量小于1 cell·mL-1.试验期间,按4～6 d间隔,以水处理系统循环处理养殖水12 h,以去除氨氮、亚硝基氮、有机物、悬浮物与细菌等.养殖约60 d后,视水质监测结果增加粗滤和泡沫分离次数,并辅以生石灰水调节循环水pH.在128d全程养殖中,未用药和换水,水处理系统有效控制养殖水质指标在虾生长合适范围内,试验池各指标平均值为:浑浊度13.9 NTU,pH 8.08,氧化还原电位399 mV,NH3-Nt(NH3-Nm)0.267(0.015)mg·L-1.,NO2--N 0.203 mg·L-1,CODMn10.34 mg·L-1.同时获得良好的养殖效果:收获虾平均体重13.56 g,成活率59.6%,单位水体产量4.27 k·m-3,饵料系数1.01.据试验结果与凡纳滨对虾养殖特点,提出了虾类室内工厂化养殖循环水调控模式.     

河蟹人工育苗池水循环净化处理技术研究

采取在养殖池内投放和接触氧化水循环处理装置内接种挂膜光合细菌、硝化细菌和放线菌等环境有益微生物 ,并与微藻、光合细菌等活饵料应用技术相结合的池水净化循环处理技术 ,通过基础试验和生产性试验进行了研究考察 ,结果表明本方法可使育苗池水循环利用 ,降低生产成本 ,减少对周边水环境的污染。试验苗池溶解氧 (DO)高于 7 5mg/L ,氨氮低于 0 5mg/L ,水质明显优于对照苗池 ,符合河蟹育苗要求。试验苗池蟹苗总成活率 19 4 % ,产量 175 8g/m3 ,蟹苗成活率、产量和质量均明显优于对照苗池     

罗氏沼虾育苗水质变动因子及处理技术的研究

针对目前罗氏沼虾育苗生产操作流程,作者研究了育苗池中三态氮、ＣＯＤ 及ｐＨ 等水质变化状况,其特点是这些化学指标无明显的昼夜变化,但ＮＨ３－Ｎ、ＮＯ２－ －Ｎ 含量较高,并呈现波动式上升的趋势,ＣＯＤ 含量较为稳定。从育苗安全性需要出发,还研究了育苗水的预处理模式以及投饵、换水、施药对育苗池水质的影响,结果表明,对河口天然水进行预处理是必要的,作为常规在操作管理上坚持每天彻底排污、适时适量换水、合理用药能有效控制育苗水的水质状况,即使采取高密度（ Ｚ１：２２万尾／ｍ ２）育苗也能获得较高的出苗率     

Effect of dietary β‐1,3‐glucan on the immune response of Litopenaeus vannamei exposed to nitrite‐N

β‐1,3‐Glucan with 1.0 g kg^?1 was supplemented to a basal diet [control (C)] with different feeding schedules: permanently β‐1,3‐glucan diet (BG) and 14 days BG–14 days control diet (C + BG). Growth and immunological responses [respiratory burst (RB), superoxide dismutase (SOD), catalase (CAT), lysozyme and total protein] in haemolymph, hepatopancreas and muscle of Litopenaeus vannamei were recorded after 84‐day feeding and exposure to nitrite‐N (20 mg L^?1) for 120 h. β‐1,3‐Glucan administration did not affect growth performance. However, as compared with control, elevated CAT and lysozyme activities were seen in haemolymph of both BG groups, while significantly higher activities of SOD, lysozyme and RB in hepatopancreas, and higher activities of CAT and lysozyme in muscle were only seen in C + BG group. After nitrite‐N stress, significantly higher haemolymph protein, and hepatopancreas activities of lysozyme and RB were observed in both BG groups, but significantly higher activities of haemolymph SOD was only seen in C + BG group. The mortality in groups BG and C + BG was significantly lower than that in group C, but C + BG group showed a trend of higher nitrite‐N resistance compared with BG group. Considering dietary cost and immunostimulatory effects, the feeding schedule with 14 days BG–14 days control diet is more recommended.     

Transference of heavy metals (Hg,Cu, Pb and Zn) with the trophic structure in a polyculture pond: evidence from nitrogen stable isotope

Concentrations of heavy metals, including Hg, Cu, Pb and Zn, in sediment and different organisms as well as the transference through the food web in a polyculture pond were investigated. The δ¹⁵N values of consumers showed a gradual enrichment with increasing trophic positions from the filter‐feeding bivalves (δ¹⁵N = 10.93 on average) to the predators (δ¹⁵N ≥ 12.59 for all crustacean and fish). Concentrations of heavy metals in sediments followed the decreasing order: Cu ≈ Zn > Pb > Hg, while in organisms, the order was Zn > Cu > Pb > Hg. Concentration of Cu was negatively related to the δ¹⁵N values of the animal tissues (P < 0.05), indicating the decrease in the Cu concentration with increasing trophic positions. Concentrations of Hg, Pb or Zn did not show significant relationship to the trophic positions. Food sources and feeding guilds of organisms might be more important factors determining the heavy metal concentrations in the body tissues of aquatic animals than their trophic positions.     

多因子交互作用对菊花江蓠氮、磷吸收速率的影响

在单因子试验的基础上,从各因子的生长适宜区间内分别选取10个盐度梯度、10个光照梯度和10个温度梯度,以及10个NO3-N浓度梯度、10个NH4-N浓度梯度和10个PO4-P梯度,采用均匀设计方法,考察各因子及其交互作用对菊花江蓠N、P吸收速率的影响,通过回归分析得到:温度、光照与NO3-N、NH4-N间存在着很明显的交互作用关系,它们共同作用影响着海藻对NO3-N、NH4-N的吸收速率;对PO4-P的吸收速率,仅受到温度及PO4-P共同作用的影响;而对TIN及PO4-P的吸收却都受到N×P交互作用的影响。     

对虾养殖中后期虾塘沉积物的硝化与反硝化作用

2009年7～8月,通过使用乙炔抑制技术对对虾养殖池塘的投饵区和非投饵区沉积物硝化与反硝化速率进行了测定,并同时用气相色谱法测定了虾塘表层N2O浓度.结果表明,虾塘沉积物硝化、反硝化和硝酸盐还原速率分别为10.70～337.47 μmol/m2·h、1.10～17.92 μmol/m2·h、0.090～7.48 mmol/m2·h,虾塘表层N2O浓度为5.98～10.90 nmol/L,海-气交换通量为1.76～3.89μmol/m1·d.虾塘硝化与反硝化作用较为复杂,不仅存在着显著的区域性差异,而且呈现出明显的养殖季节变化特征,其中8月中旬硝化与反硝化速率达到最高值,而在整个养殖季节,投饵区硝化速率约为非投饵区的2～10倍,反硝化速率约为非投饵区的1～4倍.反硝化作用在虾塘生态系统的氮循环中扮演着重要角色,其日无机氮去除量为2.80 g/d,占虾塘无机氮总输入的2.34%,占总输出的2.56%.     

鹅源H5N1亚型禽流感病毒新疆分离株A/Goose/XJYL/10/2003HA基因的克隆和序列测定与分析

根据已发表的H5N1亚型禽流感病毒的HA基因全序列,设计了1对引物,对禽流感病毒新疆株A/Goose/XJYL/10/2003(H5N1)提取RNA,经RT-PCR扩增后将其克隆到pMD18-T载体上,获得长为1758bp的HA全基因序列。序列测定后,分析结果表明,本试验株与广东、香港和东南亚等不同地区的H5N1禽流感病毒HA的核甘酸序列的同源率很高,其氨基酸切割位点附近具有高致病性禽流感病毒的特征。系统进化树分析表明,新疆株为独立分支,属于欧亚种系。     

Survival in Pond Water of Four Reoviruses Isolated from Aquatic Animals

The viabilities of golden shiner virus (GSV), chum salmon virus (CSV), oyster reovirus 13P2 (13P2). and catfish reovirus (CRV) were compared following viruses incubation in pond water samples held at 4°. 20°, 25°, and 30°C for one month. At the three higher temperatures tested, viral infectivity was lost by day 15 for GSV, day 20 for CSV, and day 10 for CRV and 13P2. At 4°C. no infectious GSV was detected at day 15, while the other viruses showed little or no loss of infectivity during the 30-day incubation period. The survival of these viruses in natural waters appears to be sufficient to sustain fish-to-fish transmission.     

Trophic overlap between non‐native brown bullhead (Ameiurus nebulosus) and native shortfin eel (Anguilla australis) in shallow lakes

We quantified trophic overlap between the invasive, non‐native catfish brown bullhead (Ameiurus nebulosus) and the New Zealand native shortfin eel (Anguilla australis) in four peat and riverine lakes using stable isotope (δ¹³C and δ¹⁵N) and gut content analyses. Across all lakes and fish sizes over the austral spring–summer period, shortfin eel guts were dominated numerically by fish prey (57% occurrence cf 42% in brown bullhead), while Diptera larvae were most commonly encountered in guts of brown bullhead (45% cf 14% in eels). Significant differences in % composition of animal contents in guts were detected between fish species and sampling occasions (n = 4) but not between lakes. In contrast, stable isotope signatures of brown bullhead and shortfin eel did differ significantly between lakes but not between sampling occasions, indicating enduring sources of nutrition despite apparently differing ingestion patterns over time. The R mixing model MixSIAR indicated that shortfins likely assimilated higher proportions of fish prey carbon compared to brown bullheads, which appeared to show greater assimilation of invertebrates, consistent with the results of gut content analyses. Isotopic niche regions, calculated in nicheROVER using probabilistic ellipses, indicated that shortfin eels occupied at least c.60% of brown bullhead trophic niche, which occupied less than 30% of eel trophic niche in all but one lake. These estimates suggest that brown bullhead has higher potential to influence shortfin eel nutrition than vice versa, or that a broad trophic niche occupied by eels provides resilience to the effects of overlapping consumption patterns with invasive omnivores.     

Effects of dietary α‐ketoglutarate supplementation on the antioxidant defense system and HSP 70 and HSP 90 gene expression of hybrid sturgeon Acipenser schrenckii ♀ × A. baerii ♂ exposed to ammonia‐N stress

This study was conducted to determine the effects of dietary α‐ketoglutarate (AKG) supplementation on the antioxidant defense system and gene expression of heat shock protein (HSP) 70 and HSP 90 in hybrid sturgeons Acipenser schrenckii ♀ × A. baerii ♂ exposed to ammonia‐N stress. A 2 × 3 factorial experiment was arranged, in which each diet (0%, 1% AKG) was randomly assigned to 0.25 (control) 5 and 10 mg L^?1 ammonia‐N groups with three replicate aquaria for each 72 h. The 10 mg L^?1 ammonia‐N significantly increased serum ammonia concentrations and intestinal Gln concentrations and GS activity compared with the 0.25 or 5 mg L^?1 ammonia‐N groups. The intestinal Gln concentration and GS activity increased, and the serum ammonia concentration decreased, in fish given dietary supplementation of 1.0% AKG compared with fish given diets without AKG. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity in serum, gills and intestines decreased when fish were exposed to 5 or 10 mg L^?1 ammonia‐N, and their activity increased in fish given diets with 1% AKG. Catalase in the serum and gills decreased when fish were exposed to 5 or 10 mg L^?1 ammonia‐N and increased in fish given diets with 1% AKG. The 10 mg L^?1 ammonia‐N or 1% AKG supplementation increased HSP 70 and HSP 90 gene expression in the liver. The increased activity of antioxidant enzymes, and increased HSP 70 and HSP 90 gene expression in fish fed diets containing 1% AKG suggested higher tolerance to ammonia‐N stress.     

Partial replacement of fish oil with terrestrial lipid blend and effects on growth performance,body composition,immune parameter and growth‐related genes in yellow drum (Nibea albiflora)

The imbalance of fish oil (FO) supply and demand has motivated efforts to identify an alternative for aqua feed. An 8‐week feeding trial was conducted to evaluate the effects of dietary fish oil partial replacement with mixed oil from linseed and lard (1:1) on growth, body composition and immunity when the N3 long‐chain polyunsaturated fatty acid (N3 LC‐PUFAs) requirement is met for Nibea albiflora. Two types of experimental diets were formulated with 100% fish oil (FO) or 69% mixed oil (Mix). The results indicated that the Mix diet significantly improved the specific growth rate (SGR), weight gain (WG), feed efficiency ratio (FER), muscle tissue growth hormone receptor (GHR), insulin‐like growth factor 1 (IGF1) and insulin‐like growth factor 1 receptor (IGF1R) gene expression of the yellow drum (p < .05). No significant difference in the survival rate (SR), feed intake (FI), hepatosomatic index (HSI), viscerosomatic index (VSI), condition factor (CF), N3 PUFA percentage, liver antioxidant enzyme activities or pro‐inflammatory gene expression was observed between the two treatments. Therefore, terrestrial blend lipid from linseed and lard could be used as an alternative for dietary fish oil without compromising growth performance and immunity for the juvenile yellow drum.